One of the activities associated with the completion of an oil or gas well is the perforation of a well casing. During this procedure, perforations, such as passages or holes, are formed in the casing of the well to enable fluid communication between the well bore and the hydrocarbon producing formation that is intersected by the well. These perforations are usually made with a perforating gun loaded with shaped charges. The gun is lowered into the wellbore on electric wireline, slickline or coiled tubing, or other means until it is adjacent the hydrocarbon producing formation. Thereafter, a surface signal actuates a firing head associated with the perforating gun, which then detonates the shaped charges. Projectiles or jets formed by the explosion of the shaped charges penetrate the casing to thereby allow formation fluids to flow from the formation through the perforations and into the production string for flowing to the surface.
Many oil well tools incorporate a high-order detonation as part of their operation. It is desirable to ensure that such high-order detonations do not unintentionally activate the oil well tools at the surface or at an undesirable location in the wellbore. The present disclosure relates to methods and devices for preventing unintended detonation of perforating guns and other wellbore devices that use high-order detonations.